added flood control to server

src/server/player.cpp

@@ -15,7 +15,7 @@
 
 #include "player.hpp"
 
-player::player(const std::string& n, config& cfg) : name_(n), cfg_(cfg)
+player::player(const std::string& n, config& cfg) : name_(n), cfg_(cfg), flood_start_(0), messages_since_flood_start_(0)
 {
 	cfg_["name"] = n;
 	mark_available(true);
@@ -35,3 +35,35 @@ config* player::config_address()
 {
 	return &cfg_;
 }
+
+namespace
+{
+	const size_t MaxMessages = 4;
+	const size_t TimePeriod = 5;
+}
+
+
+bool player::silenced() const
+{
+	return messages_since_flood_start_ > MaxMessages;
+}
+
+bool player::is_message_flooding()
+{
+	const time_t now = time(NULL);
+	if(flood_start_ == 0) {
+		flood_start_ = now;
+		return false;
+	}
+
+	++messages_since_flood_start_;
+
+	if(now - flood_start_ > TimePeriod) {
+		messages_since_flood_start_ = 0;
+		flood_start_ = now;
+	} else if(messages_since_flood_start_ == MaxMessages) {
+		return true;
+	}
+
+	return false;
+}

src/server/player.hpp

@@ -14,6 +14,8 @@
 #ifndef PLAYER_HPP_INCLUDED
 #define PLAYER_HPP_INCLUDED
 
+#include <ctime>
+
 #include "../config.hpp"
 
 #include <string>
@@ -29,9 +31,15 @@ public:
 
 	config* config_address();
 
+	bool silenced() const;
+	bool is_message_flooding();
+
 private:
 	std::string name_;
 	config& cfg_;
+
+	time_t flood_start_;
+	int messages_since_flood_start_;
 };
 
 #endif

src/server/server.cpp

@@ -132,6 +132,8 @@ private:
 	std::map<std::string,config> redirected_versions_;
 	std::map<std::string,config> proxy_versions_;
 
+	bool ip_exceeds_connection_limit(const std::string& ip);
+
 	bool is_ip_banned(const std::string& ip);
 	std::string ban_ip(const std::string& mask);
 	std::vector<std::string> bans_;
@@ -176,6 +178,19 @@ server::server(int port, input_stream& input, const config& cfg, size_t nthreads
 	join_lobby_response_.add_child("join_lobby");
 }
 
+bool server::ip_exceeds_connection_limit(const std::string& ip)
+{
+	const size_t MaxConnections = 5;
+	size_t connections = 0;
+	for(player_map::const_iterator i = players_.begin(); i != players_.end(); ++i) {
+		if(network::ip_address(i->first) == ip) {
+			++connections;
+		}
+	}
+
+	return connections > MaxConnections;
+}
+
 bool server::is_ip_banned(const std::string& ip)
 {
 	for(std::vector<std::string>::const_iterator i = bans_.begin(); i != bans_.end(); ++i) {
@@ -255,7 +270,7 @@ std::string server::process_command(const std::string& cmd)
 		out << "---";
 	} else if(command == "metrics") {
 		out << metrics_;
-	} else if(command == "ban") {
+	} else if(command == "ban" || command == "kban") {
 
 		if(i == cmd.end()) {
 			out << "BAN LIST\n---\n";
@@ -268,7 +283,12 @@ std::string server::process_command(const std::string& cmd)
 
 			for(player_map::const_iterator j = players_.begin(); j != players_.end(); ++j) {
 				if(j->second.name() == mask) {
+					const std::string nick = mask;
 					mask = network::ip_address(j->first);
+					if(command == "kban") {
+						network::queue_disconnect(j->first);
+						out << "Kicked " << nick << ", ";
+					}
 					break;
 				}
 			}
@@ -304,9 +324,12 @@ std::string server::process_command(const std::string& cmd)
 
 		for(player_map::const_iterator j = players_.begin(); j != players_.end(); ++j) {
 			if(j->second.name() == nick) {
-				throw network::error("",j->first);
+				network::queue_disconnect(j->first);
+				return "kicked " + nick;
 			}
 		}
+
+		out << "could not find user '" << nick << "'\n";
 	} else {
 		out << "command '" << command << "' is not recognized";
 		out << "available commands are: msg <message>, status, metrics, ban [<nick>], unban <nick>, kick <nick>";
@@ -344,13 +367,20 @@ void server::run()
 			network::process_send_queue();
 
 			network::connection sock = network::accept_connection();
-			if(sock && is_ip_banned(network::ip_address(sock))) {
-				std::cerr << "rejected banned user '" << network::ip_address(sock) << "'\n";
-				network::send_data(construct_error("You are banned."),sock);
-				network::disconnect(sock);
-			} else if(sock) {
-				network::send_data(version_query_response_,sock);
-				not_logged_in_.add_player(sock);
+			if(sock) {
+				const std::string& ip = network::ip_address(sock);
+				if(is_ip_banned(ip)) {
+					std::cerr << "rejected banned user '" << ip << "'\n";
+					network::send_data(construct_error("You are banned."),sock);
+					network::disconnect(sock);
+				} else if(ip_exceeds_connection_limit(ip)) {
+					std::cerr << "rejected ip '" << ip << "' due to excessive connections\n";
+					network::send_data(construct_error("Too many connections from your host."),sock);
+					network::disconnect(sock);
+				} else {
+					network::send_data(version_query_response_,sock);
+					not_logged_in_.add_player(sock);
+				}
 			}
 
 			config data;
@@ -645,8 +675,17 @@ void server::process_data_from_player_in_lobby(const network::connection sock, c
 	//of the sender, and forward it to all players in the lobby
 	config* const message = data.child("message");
 	if(message != NULL) {
-		const player_map::const_iterator p = players_.find(sock);
+		const player_map::iterator p = players_.find(sock);
 		wassert(p != players_.end());
+
+		if(p->second.silenced()) {
+			return;
+		} else if(p->second.is_message_flooding()) {
+			network::send_data(construct_server_message("Warning: you are sending too many messages too fast. Your message has not been relayed.",
+			                                            lobby_players_),p->first);
+			return;
+		}
+
 		(*message)["sender"] = p->second.name();
 
 		truncate_message((*message)["message"]);
@@ -1097,7 +1136,4 @@ int main(int argc, char** argv)
 	}
 
 	return 0;
-}
-
-
-
+}